This Methodologies for Improving Measurement of Alcohol Consumption and Problems research component continues Center research to improve precision of alcohol measurement, make innovations in research design and measures for clinical populations. To accomplish this we specify three new methodological sub-studies. Sub-Study 1 analyzes data from wireless (cell-phone) and landline telephone samples in the 2009/10 (N12) and 2014/15 (N13) National Alcohol Surveys. The wireless-only population is projected to comprise 30% of the U.S. population by 2015. Thus, reaching wireless-only households is crucial to securing nationally representative samples. Sub-Study 1 critically examines differences in alcohol-related outcomes by telephone interviewing mode and evaluates methods, such as propensity score, sample selection approaches, and weighting in landline-only samples to adjust for omission/under-representation of wireless using individuals. Results will inform the alcohol field and optimize future national surveys. Addressing NIAAA priorities of research on special populations, Sub-Study 2 focuses on analysis of biases from case-crossover studies on the relative risk of injury and alcohol and alcohol-attributable fraction in cross-national emergency room studies. It applies new and innovative methods towards AAF estimation and modifications that have not previously explored cross-nationally. Findings will improve the case-crossover design by accounting for key situational confounders of the alcohol-injury relationship. Results are also expected to have domestic and international impact on global burden of disease estimates and thereby on the worldwide public health significance of alcohol. Sub-Study 3 examines variability in item functioning of the AUDIT, a widely used alcohol use disorder screening tool, using item response theory (IRT) analyses on cross-national and NAS data. This sub-study addresses the NIAAA research priority of better understanding differential reliability and validity of AUD diagnoses among demographic, ethnic, and cultural subgroups. It will identify individual and macro-level factors, such as drinking culture and gender inequity, in item response biases for the AUDIT. Findings are expected to inform clinical and research guidelines for improved alcohol screening and measurement, tailored to specific subgroups, both cross-nationally and within the US.